Not Applicable.
Not Applicable
The field of invention is switch lever lock outs for locking switch levers in a desired position, and more particularly to key operated switch lever lock outs.
Switches are used in many applications to control the flow of electrical energy. The switches can be used to redirect electrical energy from one circuit to another, and can be used to stop the flow of electrical energy through a circuit. In both cases the circuits become de-energized, that is without a voltage. One particular type of switch is a circuit breaker which cuts off the flow of electrical energy when the flow of electrical energy through the switch exceeds a predetermined value. Many of these circuit breakers include a lever which is movable between an xe2x80x9cOnxe2x80x9d position and an xe2x80x9cOffxe2x80x9d position.
Maintenance personnel often use a circuit breaker to interrupt the flow of electrical energy through a circuit when the circuit, or electrical components connected thereto, require maintenance. The circuit breaker, however, is often remote from the location requiring maintenance. Therefore, it is desirable to lock out the circuit breaker to prevent an individual from inadvertently energizing the circuit while maintenance is being performed.
Known circuit breaker lock out assemblies engage the circuit breaker lever to prevent unauthorized movement of the lever. Lock outs, such as disclosed in U.S. Pat. Nos. 5,593,020; 5,794,760; and 5,900,600, include a lock arm cantilevered from a lock rail. The lock arm includes a head which engages or covers the circuit breaker lever to prevent unauthorized movement of the lever. This particular type of lock out requires the lock rail be positioned adjacent the specific circuit breaker being locked out. If there is insufficient space adjacent the specific circuit breaker for a lock rail, these lock outs cannot be used. Therefore, a need exists for an improved lock out which can be used with or without a lock rail, and if a lock rail is used, the lock rail can be located remote from the specific circuit breaker being locked out.
The present invention provides a switch lever lock out assembly engagable with a switch. The assembly includes a lock out body engageable with a switch to prevent operation of the switch. A lever engaging member is mounted to the body, and has a lock position and an unlock position. In the lock position, the lever engaging member prevents disengaging the body from the switch. A blocking member is movably fixed to the body, and is engageable with the lever engaging member to prevent movement of the lever engaging member relative to the body when the lever engaging member is in the lock position.
The blocking member and body can be locked relative to each other by a latch member engaging a latching member. The latch member is fixed relative to one of the body and the blocking member. The latching member is engagable with the latch member in an engaged position, and fixed relative to the other of the body and the blocking member, wherein in the engaged position, the blocking member is locked relative to the lever engaging member in the lock position. A key is engageable with at least one of the latch member and the latching member to disengage the latching member from the latch member and allow the blocking member to move relative to the body to allow the lever engaging member to move from the lock position to the unlock position.
In another aspect of the invention, the key is attached to a tether forming part of the assembly. The tether has a first end and a second end, and the key is slidably fixed to the tether for slidable movement between said first and second ends. The key can be locked in a lock rail fixed within an area defined by the tether either inside or outside the circuit breaker enclosure.
A general objective of the present invention is to provide a lock out assembly which prevents unauthorized actuation of a switch. The present invention provides a lock out assembly which requires a key to disengage the assembly from the switch to allow operation of the switch.
Another objective of the present invention is to provide a lock out assembly which can be used with a lock rail which does not require aligning the lock rail with the switch being locked out. This objective is accomplished by providing a lock out assembly requiring a key, and fixing the key onto a tether, wherein the key is locked to the lock rail fixed within an area defined by the tether.